We develop a weak coupling approach to superconductivity in twisted bilayer graphene, starting from the Fermi liquid regime. A key observation is that near half filling, the fermiology consists of well nested Fermi pockets derived from opposite valleys, leading to enhanced valley fluctuation, which ...
Tunable second harmonic generation in twisted bilayer graphene. Matter 3, 1361–1376 (2020). Article Google Scholar Kim, C.-J. et al. Stacking order dependent second harmonic generation and topological defects in h-BN bilayers. Nano Lett. 13, 5660–5665 (2013). Article ADS Google Scholar ...
Moiré superlattices formed by twisting trilayers of graphene are a useful model for studying correlated electron behaviour and offer several advantages over their formative bilayer analogues, including a more diverse collection of correlated phases and
Counterintuitive temperature dependence of isospin flavor polarization has recently been found in twisted bilayer graphene, where unpolarized electrons in a Fermi liquid become a spin–valley polarized insulator upon heating. So far, the effect has been limited tov=+/1 (one electron/hole per ...
Recent mean-field calculations suggest that the superconducting state of twisted bilayer graphene exhibits ei-ther a nematic order or a spontaneous breakdown of the time-reversal symmetry. The two-dimensional character of the material and the large critical temperature relative to the Fermi energy dicta...
Researchers from University of Illinois Describe Findings in Physics (Corrugation-driven Symmetry Breaking In Magic-angle Twisted Bilayer Graphene) By a News Reporter-Staff News Editor at Electronics Newsweekly – Current\nstudy results on Physics have been published. According to news reporting from U...
This four-electron condensate, instead of superconductivity, shows a spontaneous breaking of time-reversal symmetry. Our results suggest that twisted bilayer graphene is an especially promising platform to study different types of condensates, beyond the pair-condensate paradigm.Maccari, I....
Symmetry, maximally localized Wannier states, and low energy model for the twisted bilayer graphene narrow bandsJian KangOskar VafekAPS March Meeting Abstracts
The discovery of unconventional superconductivity in magic-angle twisted bilayer graphene (tBLG) supported the twist-angle-induced flat band structure predictions made a decade earlier. Numerous physical properties have since been linked to the interlaye
Most work has focused on the zero-magnetic-field phase diagram, but here we show that twisted bilayer graphene in a finite magnetic field hosts a cascade of ferromagnetic Chern insulators with Chern number ∣C∣ = 1, 2 and 3. The emergence of the Chern insulators is driven by the ...